Background: This study on gut feelings investigates the correlation between microdiversity in the gut and cognitive reactivity in the brain with sex as a potential moderator. Research on potential...Show moreBackground: This study on gut feelings investigates the correlation between microdiversity in the gut and cognitive reactivity in the brain with sex as a potential moderator. Research on potential correlations and moderators is relevant to gain further insight into the networks involved in the gut-brain axis. The findings can influence treatment approaches in the field of clinical psychology to a greater focus on the gutbrain axis. Two hypotheses were examined: 1) a higher microdiversity in the gut is correlated with less emotion regulation difficulties, and 2) there are sex differences in the correlation between microdiversity and emotion regulation. Methods: This research was an observational between-subjects design with a total number of 75 participants. The primary outcome was the alpha score, assessed with the Shannon Index, which gives insight into individual microdiversity. The Difficulties in Emotion Regulation Scale was used to assess self-reported difficulties in emotion regulation to have insight into individual cognitive reactivity. Sex was conceptualised as the moderator variable. A correlational analysis for alpha scores and DERS scores was carried out, followed by a multiple regression analysis, which tested for a moderation with the variable sex. Results: There was no evidence for a negative correlation between high microdiversity and few emotion regulation difficulties. Sex did not have a significant moderation on this correlation either. Implications: Further research is needed on the gut-brain axis and sex differences in gut microdiversity and emotion regulation to adapt the treatment of stress-related disorders such as post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), or other anxiety-related disorders from a cognitive- to a more holistic approach.Show less